Elizabeth Warren is on the rise among Democratic voters, but she and other Democrats are less popular with the overall electorate, raising concerns about a bruising primary that could go on for the better part of the next year, a new NPR/PBS NewsHour/Marist poll finds.

The survey also finds President Trump continuing to struggle, with economic concerns seemingly starting to affect his standing, leaving a cloudy picture about the 2020 presidential election.

Here are some key findings from the poll and how the results indicate what's ahead in 2020:

The Democrats

Warren finds herself in a strong position with Democratic voters ahead of Thursday's Democratic presidential debate.

Seventy-five percent of Democratic voters now say they have a favorable impression of Warren — that's up from 53% in January, a 22-point jump from the last time the poll asked the favorability of candidates or potential candidates.

What's more, the percent of those saying they have a negative impression has gone down from 17% to 11%.

"Elizabeth Warren seems to be on the verge of starting to make significant and serious inroads into this contest," said Lee Miringoff, director of the Marist Institute for Public Opinion, which conducts the poll. He added, "Heading into the debate, she's very well-positioned."

Biden holding up

Former Vice President Joe Biden, who leads in most national polls of the Democratic contest, is also well-liked, but he has seen a decline since January — 71% of Democrats say they have a positive impression of Biden, a 5-point drop, and 22% don't, an 10-point increase in his negative rating.

"One of the initial senses of what Joe Biden presented was that he seemed to be less of a risk," Miringoff said, "but his performance so far has not been gaffe-proof, and as a result, people are not as comfortable and that opened up the door for others, and particularly Warren."

Biden has been taking most of the slings and arrows of his Democratic opponents, given his lead in the race, and his campaign would argue that he has held up well considering.

The broader electorate isn't quite sold on either Biden or Warren. Biden has the higher name recognition, and voters overall give him just a 45% favorable, 46% unfavorable rating. Voters are similarly split on Warren, who gets a 41% favorable and 42% unfavorable rating.

Sanders popular with the base but not the general electorate

Bernie Sanders, who has retained his loyal following, has seen an increase in his favorability rating among Democrats since officially declaring his candidacy. The Vermont senator has gone from 57% positive in January to 66% now. But it's a different story with the broader electorate: 55% of voters say they have an unfavorable impression of Sanders, while just 38% have a positive one.

"Bernie Sanders having over 50% negative has to be concerning to Democrats looking for electability," Miringoff noted.

Harris is now better known but also unpopular with general electorate

California Sen. Kamala Harris was also tested, but the difference of views of her between the primary and general election electorate are most striking. Harris has gone up 20 points with Democrats, as she has increased her name recognition, going from 36% favorable in January to 56% now. Back then, more than half of Democrats were either unsure or never heard of her. That's down to just a quarter of Democrats now.

So, she's worn well with Democrats, but not with a general electorate so far. Among registered voters, she has a 31% favorable, 42% unfavorable rating. (The poll did not test the favorability of the candidates with a general-election electorate back in January.)

"When you look at the national electorate," Miringoff said, "there's still a lot of work to be done on the part of Democrats to start attracting a positive reaction."

Democrats want to beat Trump

How the candidates fare with a general-election audience could be critical, as Democrats are increasingly saying beating Trump is more important than whether a candidate shares their position on most issues. In this poll, 58% said that, an increase from 54% in July and 46% in June.

The broader electorate continues to be split on whether the ideas they've heard from Democrats are going to take the country in the right direction (46%) or the wrong one (43%). That's a slight improvement from July when it was the mirror opposite. Still, more independents say their ideas move the country in the wrong direction (49%) than right one (42%).

The president's numbers

President Trump doesn't fare much better than his potential Democratic opponents. His overall approval rating is low (41%), a near-record number of people "strongly disapprove" of the job he's doing (45%), a record number disapprove of his handling of foreign policy (56%) and a majority say they will "definitely" vote against him in 2020 (52%).

What's more, while the economy is buoying Trump — 51% overall and 53% of independents rate it as excellent or good — he has seen something of a bad economic summer. While the economy is still growing and unemployment is low, economic forecasts have turned gloomy with warning signs of a coming recession.

Trump's economic handling has taken a hit. More now disapprove (48%) than approve (47%) of it, a turnaround from July when a majority (53%) approved of his handling of the economy.

Overall, Americans who responded were split, 47% to 46% on whether Trump's policies have strengthened or weakened the economy. And the number of people who think his policies have weakened the economy has increased 6 points since July.

Just 5% of Republicans think he will lose, while 11% of Democrats think he will win and 14% are unsure. Independents, 49% to 32% think he's going to win.

Methodology

The survey of 1,314 adults was conducted with live callers via telephone by The Marist Poll and has a margin of error of 3.6 percentage points. There are 1,160 registered voters with a margin of error of 3.8 percentage points. There are 542 Democrats and Democratic-leaning independents with a margin of error of 5.6 percentage points.

Copyright 2019 NPR. To see more, visit https://www.npr.org.

RACHEL MARTIN, HOST:

The next Democratic debate is tomorrow. So who is best positioned to win over voters? A new NPR/PBS NewsHour/Marist poll finds that Senator Elizabeth Warren is in a strong place, registering as the, quote, "most well-liked of all the Democratic candidates." But Americans overall aren't that enthusiastic about this crop of Democrats or, for that matter, the incumbent president.

Let's dig into the poll results a little deeper with NPR senior political editor and correspondent Domenico Montanaro. Hi, Domenico.

DOMENICO MONTANARO, BYLINE: Hi, Rachel.

MARTIN: So pretty good news for Senator Warren. What were you asking voters specifically about likability?

MONTANARO: Yeah, we're asking voters, you know, Democrats in particular, whether they had a favorable impression or unfavorable impression of the candidates who are going to be on stage tomorrow night. And Warren, you know, really popped. She's gone up 22 points since January. More than three-quarters of Democrats like her. Former Vice President Biden does pretty well, as does Bernie Sanders. But it's a different story for the general election for all of them.

MARTIN: And President Trump himself is not faring well either.

MONTANARO: No, he's not. I mean, you know, these Democratic candidates, it's essentially partisanship that's slipping in. You have them pretty split amongst the general election overall - Bernie Sanders, not very well-liked overall - 55%. And President Trump himself, his approval rating is only 41%, among the highest he's had for strongly disapproving at 45%. And it looks like a lot of the economic worries over the summer are starting to take a bit of a toll on him.

MARTIN: So does that mean that people think - clearly they have issues with his policies. According to your poll, does it mean they think he's going to lose?

MONTANARO: Actually, no, (laughter) that's kind of surprising here that most Americans or more Americans think he's going to win reelection than lose by a 46%-to-37% margin. You know, people have a mostly positive outlook on the economy, and that really is buoying him right now.

MARTIN: We also have a result from a special election in North Carolina that we need to talk about. This was for the House seat that was up for grabs. The Republican won, but the margin of victory was still pretty small. And this was someone President Trump had campaigned for. What should he and his reelection team take from this, if anything?

MONTANARO: Well, look, millions were spent by both sides on this. The Republican, Dan Bishop, won by only two percentage points. President Trump is already out tweeting about this, taking a measure of credit for going in there and helping put him over the edge. Less than 4,000 votes decided this race, and I think the most important thing is kind of what it means for politics going forward.

You know, Trump won this district by 12 points, and there are almost 30 districts that are held by Republicans where Trump did worse and won that district. So you have the idea, though, of how things are sort of being reshaped because this is a place where Bishop wound up winning and kind of juicing rural areas to be able to win. The suburban areas, the sort of wealthy areas in and around Charlotte, wound up going for McCready.

I think we're seeing a big crackup in the way and the kinds of voters who are going for each party, and, you know, it's going to be really interesting to see what that means for 2020. When it comes to the House races, you know, I'm not sure there are enough seats for Republicans to target without being able to win some of those suburbs.

MARTIN: All right, Domenico Montanaro, NPR's senior political editor and correspondent, breaking down the results of a recent poll and getting ready as we all look forward to the next Democratic presidential debate tomorrow night. Domenico, thank you.